1. Field of the Invention
The present invention relates to a piezoelectric vibrating piece, a piezoelectric vibrator, an oscillator, an electronic apparatus and a radio controlled timepiece.
2. Background Art
For example, in a cellular phone or a portable information terminal apparatus, a piezoelectric vibrator utilizing crystals or the like is often used as a device which is used in a time source, a timing source of a control signal or the like, and a reference signal source or the like. As a piezoelectric vibrator of this type, a piezoelectric vibrator is known in which a piezoelectric vibrating piece is hermetically sealed within a package in which a cavity is formed.
In the related art, the piezoelectric vibrating pieces having various shapes are known, and as one of them, a piezoelectric vibrating piece, which includes a pair of vibrating arm sections that are disposed by being spaced in a width direction, a base section that is connected to each of base ends of the pair of vibrating arm sections, and a support aim section that is connected to the base section between the pair of vibrating arm sections, is known (JP-A-2003-163568, JP-A-2006-345517 and JP-A-2006-345519). The piezoelectric vibrator is configured by bonding a mount section that is formed in the support arm section of the piezoelectric vibrating piece and an electrode pad on the side of the package with a conductive adhesive, a metal bump or the like.
Then, the piezoelectric vibrating piece is configured such that the pair of vibrating arm sections in which excitation electrodes are formed vibrate at a predetermined frequency to separate from or approach each other by applying a voltage from external electrodes formed outside the package to the piezoelectric vibrating piece.
However, when operating the piezoelectric vibrating piece, it is known that vibration leakage (leakage of vibration energy) occurs from the mount section of the base section to the side of the package. If the vibration leakage occurs, since a resonance frequency of the piezoelectric vibrating piece is no longer stable, it is necessary to suppress the vibration leakage as much as possible. Thus, a technique for reducing the vibration leakage is known by attenuating the vibration by separating a distance between the vibrating arm sections and the mount section.